In many applicational areas, perfumes are used for masking malodors. Annoyance caused by malodors occurs frequently in daily life and impairs personal well-being. Such malodors are, for example, those resulting from substances transpired or excreted by humans, in particular, perspiration, feces and urine, odors caused by animal feces or urine, in particular, those of domestic pets, kitchen odors, such as those resulting from the preparation of onions, garlic, cabbage or fish, odors due to tobacco smoke, and in particular, cold tobacco smoke, molds and waste.
In addition, malodors are caused by many industrially produced basic materials used in cleansing agents, such as, for example, detergents and fabric softeners, or in body care products, such as, for example, soaps and cosmetics. The use of specific cosmetic preparations, such as, for example, hair dyes, hair-forming agents and depilatories, also produce malodors.
Many rubber and plastic products also produce malodors if, due to the method of their manufacture, they still contain quantities of highly odorous, volatile active ingredients.
These malodors are usually caused by particularly odorous substances which are, however, frequently only present in trace amounts. Such substances include, for example, nitrogen-containing compounds such as ammonia and amines, heterocyclic compounds such as pyridines, pyrazines, indoles, etc. and sulfur-containing compounds such as hydrogen sulfide, mercaptans, sulfides, etc.
The masking of malodors is a problem, which is difficult to handle and solve with perfume compositions. The specific unique quality of a malodor greatly restricts the use of perfumes having the various types of commonly known fragrances. Usually, it is only possible to mask malodors by means of a specially developed perfume oil having a very specific type of fragrance.
Active ingredients are, therefore, particularly advantageous when they are capable of reducing the intensity of malodors without themselves possessing any significantly intense odor or fragrance. Such active ingredients do not mask malodors but neutralize them. This has the advantage that when using such active ingredients for perfuming objects or products with malodors, perfume oils of any desired type of fragrance can be used. The consumer can, therefore, be offered a considerably broader range of fragrance types for combating malodors.
In addition, active ingredients, which neutralize malodors, provide the possibility of reducing the quantity of perfume oil previously required for masking odors. It is also possible to use less intensely odorous perfumes for combating malodors than those so far employed, which sometimes have an overpowering effect due to their high intensity.
U.S. Pat. No. 5,676,163 describes the use of aldehydes employed as perfumes for combating malodors caused by nitrogen-containing active ingredients contained in tobacco smoke.
U.S. Pat. No. 5,501,805 describes the reduction of malodors with the aid of selected perfume raw materials such as, for example, musk perfumes and salicylates.
EP A 780132 describes combating malodors using a combination of musk and citrus perfumes and peppermint oil.
U.S. Pat. No. 4,719,105 describes the use of cyclohexyl methanols and esters thereof, preferably, for use in air fresheners for combating various malodors.
U.S. Pat. No. 4,009,253 describes the use of 4-cyclohexyl-4-methyl-2-pentanone for combating malodors.
U.S. Pat. No. 5,789,010 describes reducing unpleasant aldehyde odors in triglycerides by adding an amine and masking the odor by adding a perfume aldehyde.
WO 96/31590 describes masking the odor of bleaching liquids with the aid of selected perfume raw materials.
JP B 01056798 (cf Chem. Abstr. 111, 176823) also describes masking the odor of bleaching liquids with the aid of selected perfumes, such as, for example, 2,6-di-methyl-4-heptyl acetate and 3,3,5-trimethylcyclohexyl isobutyrate.
U.S. Pat. No. 5,380,707 describes combating body odor using a musk perfume.
In Patents Nos. JP A 10120541 (cf. Chem. Abstr. 128, 326350), U.S. Pat. No. 5,559,271, JP A 05058869 (cf. Chem. Abstr. 119, 187285), JP A 2726846 (cf. Chem. Abstr. 110, 140763), JP A 03029280 (cf Chem. Abstr. 107, 238946), HU 36383 (cf. Chem. Abstr. 105, 29193) and JP A 03044781 (cf Chem. Abstr. 102, 225585) menthyl acetate or 1-menthyl acetate are described as ingredients of perfume mixtures which are suitable for combating malodors of the most varied kinds. In WO 98/27261 1-isopulegyl acetate is also mentioned as an odor-combating agent in addition to menthyl acetate.
The known agents for masking or neutralizing malodors only act in specific cases and thus, restrict the perfume manufacturer's means of combination.